<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.w3.org/1999/xhtml">
<head>
    <meta charset="UTF-8"/>
    <title>Title</title>
</head>
<body>
<div th:fragment="head">
    <div style="height: 100px;background: blue"><h1>嵌入头部</h1></div>
</div>
</body>
</html>